Revision 89a8640279f8bb78aaf778d1fc5c4a6778f18064 authored by David Howells on 30 October 2009, 13:13:26 UTC, committed by Linus Torvalds on 31 October 2009, 19:11:37 UTC
Don't pass NULL pointers to fput() in the error handling paths of the NOMMU do_mmap_pgoff() as it can't handle it. The following can be used as a test program: int main() { static long long a[1024 * 1024 * 20] = { 0 }; return a;} Without the patch, the code oopses in atomic_long_dec_and_test() as called by fput() after the kernel complains that it can't allocate that big a chunk of memory. With the patch, the kernel just complains about the allocation size and then the program segfaults during execve() as execve() can't complete the allocation of all the new ELF program segments. Reported-by: Robin Getz <rgetz@blackfin.uclinux.org> Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Robin Getz <rgetz@blackfin.uclinux.org> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent 2e2ec95
spinlock.c
/*
* Copyright (2004) Linus Torvalds
*
* Author: Zwane Mwaikambo <zwane@fsmlabs.com>
*
* Copyright (2004, 2005) Ingo Molnar
*
* This file contains the spinlock/rwlock implementations for the
* SMP and the DEBUG_SPINLOCK cases. (UP-nondebug inlines them)
*
* Note that some architectures have special knowledge about the
* stack frames of these functions in their profile_pc. If you
* change anything significant here that could change the stack
* frame contact the architecture maintainers.
*/
#include <linux/linkage.h>
#include <linux/preempt.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <linux/debug_locks.h>
#include <linux/module.h>
#ifndef _spin_trylock
int __lockfunc _spin_trylock(spinlock_t *lock)
{
return __spin_trylock(lock);
}
EXPORT_SYMBOL(_spin_trylock);
#endif
#ifndef _read_trylock
int __lockfunc _read_trylock(rwlock_t *lock)
{
return __read_trylock(lock);
}
EXPORT_SYMBOL(_read_trylock);
#endif
#ifndef _write_trylock
int __lockfunc _write_trylock(rwlock_t *lock)
{
return __write_trylock(lock);
}
EXPORT_SYMBOL(_write_trylock);
#endif
/*
* If lockdep is enabled then we use the non-preemption spin-ops
* even on CONFIG_PREEMPT, because lockdep assumes that interrupts are
* not re-enabled during lock-acquire (which the preempt-spin-ops do):
*/
#if !defined(CONFIG_GENERIC_LOCKBREAK) || defined(CONFIG_DEBUG_LOCK_ALLOC)
#ifndef _read_lock
void __lockfunc _read_lock(rwlock_t *lock)
{
__read_lock(lock);
}
EXPORT_SYMBOL(_read_lock);
#endif
#ifndef _spin_lock_irqsave
unsigned long __lockfunc _spin_lock_irqsave(spinlock_t *lock)
{
return __spin_lock_irqsave(lock);
}
EXPORT_SYMBOL(_spin_lock_irqsave);
#endif
#ifndef _spin_lock_irq
void __lockfunc _spin_lock_irq(spinlock_t *lock)
{
__spin_lock_irq(lock);
}
EXPORT_SYMBOL(_spin_lock_irq);
#endif
#ifndef _spin_lock_bh
void __lockfunc _spin_lock_bh(spinlock_t *lock)
{
__spin_lock_bh(lock);
}
EXPORT_SYMBOL(_spin_lock_bh);
#endif
#ifndef _read_lock_irqsave
unsigned long __lockfunc _read_lock_irqsave(rwlock_t *lock)
{
return __read_lock_irqsave(lock);
}
EXPORT_SYMBOL(_read_lock_irqsave);
#endif
#ifndef _read_lock_irq
void __lockfunc _read_lock_irq(rwlock_t *lock)
{
__read_lock_irq(lock);
}
EXPORT_SYMBOL(_read_lock_irq);
#endif
#ifndef _read_lock_bh
void __lockfunc _read_lock_bh(rwlock_t *lock)
{
__read_lock_bh(lock);
}
EXPORT_SYMBOL(_read_lock_bh);
#endif
#ifndef _write_lock_irqsave
unsigned long __lockfunc _write_lock_irqsave(rwlock_t *lock)
{
return __write_lock_irqsave(lock);
}
EXPORT_SYMBOL(_write_lock_irqsave);
#endif
#ifndef _write_lock_irq
void __lockfunc _write_lock_irq(rwlock_t *lock)
{
__write_lock_irq(lock);
}
EXPORT_SYMBOL(_write_lock_irq);
#endif
#ifndef _write_lock_bh
void __lockfunc _write_lock_bh(rwlock_t *lock)
{
__write_lock_bh(lock);
}
EXPORT_SYMBOL(_write_lock_bh);
#endif
#ifndef _spin_lock
void __lockfunc _spin_lock(spinlock_t *lock)
{
__spin_lock(lock);
}
EXPORT_SYMBOL(_spin_lock);
#endif
#ifndef _write_lock
void __lockfunc _write_lock(rwlock_t *lock)
{
__write_lock(lock);
}
EXPORT_SYMBOL(_write_lock);
#endif
#else /* CONFIG_PREEMPT: */
/*
* This could be a long-held lock. We both prepare to spin for a long
* time (making _this_ CPU preemptable if possible), and we also signal
* towards that other CPU that it should break the lock ASAP.
*
* (We do this in a function because inlining it would be excessive.)
*/
#define BUILD_LOCK_OPS(op, locktype) \
void __lockfunc _##op##_lock(locktype##_t *lock) \
{ \
for (;;) { \
preempt_disable(); \
if (likely(_raw_##op##_trylock(lock))) \
break; \
preempt_enable(); \
\
if (!(lock)->break_lock) \
(lock)->break_lock = 1; \
while (!op##_can_lock(lock) && (lock)->break_lock) \
_raw_##op##_relax(&lock->raw_lock); \
} \
(lock)->break_lock = 0; \
} \
\
EXPORT_SYMBOL(_##op##_lock); \
\
unsigned long __lockfunc _##op##_lock_irqsave(locktype##_t *lock) \
{ \
unsigned long flags; \
\
for (;;) { \
preempt_disable(); \
local_irq_save(flags); \
if (likely(_raw_##op##_trylock(lock))) \
break; \
local_irq_restore(flags); \
preempt_enable(); \
\
if (!(lock)->break_lock) \
(lock)->break_lock = 1; \
while (!op##_can_lock(lock) && (lock)->break_lock) \
_raw_##op##_relax(&lock->raw_lock); \
} \
(lock)->break_lock = 0; \
return flags; \
} \
\
EXPORT_SYMBOL(_##op##_lock_irqsave); \
\
void __lockfunc _##op##_lock_irq(locktype##_t *lock) \
{ \
_##op##_lock_irqsave(lock); \
} \
\
EXPORT_SYMBOL(_##op##_lock_irq); \
\
void __lockfunc _##op##_lock_bh(locktype##_t *lock) \
{ \
unsigned long flags; \
\
/* */ \
/* Careful: we must exclude softirqs too, hence the */ \
/* irq-disabling. We use the generic preemption-aware */ \
/* function: */ \
/**/ \
flags = _##op##_lock_irqsave(lock); \
local_bh_disable(); \
local_irq_restore(flags); \
} \
\
EXPORT_SYMBOL(_##op##_lock_bh)
/*
* Build preemption-friendly versions of the following
* lock-spinning functions:
*
* _[spin|read|write]_lock()
* _[spin|read|write]_lock_irq()
* _[spin|read|write]_lock_irqsave()
* _[spin|read|write]_lock_bh()
*/
BUILD_LOCK_OPS(spin, spinlock);
BUILD_LOCK_OPS(read, rwlock);
BUILD_LOCK_OPS(write, rwlock);
#endif /* CONFIG_PREEMPT */
#ifdef CONFIG_DEBUG_LOCK_ALLOC
void __lockfunc _spin_lock_nested(spinlock_t *lock, int subclass)
{
preempt_disable();
spin_acquire(&lock->dep_map, subclass, 0, _RET_IP_);
LOCK_CONTENDED(lock, _raw_spin_trylock, _raw_spin_lock);
}
EXPORT_SYMBOL(_spin_lock_nested);
unsigned long __lockfunc _spin_lock_irqsave_nested(spinlock_t *lock, int subclass)
{
unsigned long flags;
local_irq_save(flags);
preempt_disable();
spin_acquire(&lock->dep_map, subclass, 0, _RET_IP_);
LOCK_CONTENDED_FLAGS(lock, _raw_spin_trylock, _raw_spin_lock,
_raw_spin_lock_flags, &flags);
return flags;
}
EXPORT_SYMBOL(_spin_lock_irqsave_nested);
void __lockfunc _spin_lock_nest_lock(spinlock_t *lock,
struct lockdep_map *nest_lock)
{
preempt_disable();
spin_acquire_nest(&lock->dep_map, 0, 0, nest_lock, _RET_IP_);
LOCK_CONTENDED(lock, _raw_spin_trylock, _raw_spin_lock);
}
EXPORT_SYMBOL(_spin_lock_nest_lock);
#endif
#ifndef _spin_unlock
void __lockfunc _spin_unlock(spinlock_t *lock)
{
__spin_unlock(lock);
}
EXPORT_SYMBOL(_spin_unlock);
#endif
#ifndef _write_unlock
void __lockfunc _write_unlock(rwlock_t *lock)
{
__write_unlock(lock);
}
EXPORT_SYMBOL(_write_unlock);
#endif
#ifndef _read_unlock
void __lockfunc _read_unlock(rwlock_t *lock)
{
__read_unlock(lock);
}
EXPORT_SYMBOL(_read_unlock);
#endif
#ifndef _spin_unlock_irqrestore
void __lockfunc _spin_unlock_irqrestore(spinlock_t *lock, unsigned long flags)
{
__spin_unlock_irqrestore(lock, flags);
}
EXPORT_SYMBOL(_spin_unlock_irqrestore);
#endif
#ifndef _spin_unlock_irq
void __lockfunc _spin_unlock_irq(spinlock_t *lock)
{
__spin_unlock_irq(lock);
}
EXPORT_SYMBOL(_spin_unlock_irq);
#endif
#ifndef _spin_unlock_bh
void __lockfunc _spin_unlock_bh(spinlock_t *lock)
{
__spin_unlock_bh(lock);
}
EXPORT_SYMBOL(_spin_unlock_bh);
#endif
#ifndef _read_unlock_irqrestore
void __lockfunc _read_unlock_irqrestore(rwlock_t *lock, unsigned long flags)
{
__read_unlock_irqrestore(lock, flags);
}
EXPORT_SYMBOL(_read_unlock_irqrestore);
#endif
#ifndef _read_unlock_irq
void __lockfunc _read_unlock_irq(rwlock_t *lock)
{
__read_unlock_irq(lock);
}
EXPORT_SYMBOL(_read_unlock_irq);
#endif
#ifndef _read_unlock_bh
void __lockfunc _read_unlock_bh(rwlock_t *lock)
{
__read_unlock_bh(lock);
}
EXPORT_SYMBOL(_read_unlock_bh);
#endif
#ifndef _write_unlock_irqrestore
void __lockfunc _write_unlock_irqrestore(rwlock_t *lock, unsigned long flags)
{
__write_unlock_irqrestore(lock, flags);
}
EXPORT_SYMBOL(_write_unlock_irqrestore);
#endif
#ifndef _write_unlock_irq
void __lockfunc _write_unlock_irq(rwlock_t *lock)
{
__write_unlock_irq(lock);
}
EXPORT_SYMBOL(_write_unlock_irq);
#endif
#ifndef _write_unlock_bh
void __lockfunc _write_unlock_bh(rwlock_t *lock)
{
__write_unlock_bh(lock);
}
EXPORT_SYMBOL(_write_unlock_bh);
#endif
#ifndef _spin_trylock_bh
int __lockfunc _spin_trylock_bh(spinlock_t *lock)
{
return __spin_trylock_bh(lock);
}
EXPORT_SYMBOL(_spin_trylock_bh);
#endif
notrace int in_lock_functions(unsigned long addr)
{
/* Linker adds these: start and end of __lockfunc functions */
extern char __lock_text_start[], __lock_text_end[];
return addr >= (unsigned long)__lock_text_start
&& addr < (unsigned long)__lock_text_end;
}
EXPORT_SYMBOL(in_lock_functions);
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